Carpet Dry, but pad still damp

if the water came from a drain and has remained wet for that many days. its a category 3 or "black water" loss, no matter what. your carpet is junk. that guy is a hack who does not know what he is doing. nobody has mentioned walls. did he test the dry wall for moisture with a non penetrating meter. im guessing no. you need a real professional to take a look at it. but my guess is you didn't want to pay for one. by now the only thing you can do is tear out all the carpet and pad. and do 2 foot flood cuts to all the dry wall possibly affected by water. your studs may have gotten wet too so you should have them tested too. then have a contractor come in and put in drywall and carpet. this is why there are water restoration companys out there. to prevent an unnessary remodel.
its a tough lesson. i know